Electric switch



1927 F. A. BOEDTCHER ELECTRIC SWITCH Filed May 19, 1.923 2 Sheets-Sheet1 July 2 6, 1927.

F. A. BOEDTCHER ELECTRIC SWITCH 2 Sheets-Sheet 2 Filed May 19. 1923,

\lllllr x her Patented July 26, 1927.

UNITED STATES PATENT OFFICE. I

FRANZ A. BOEDTCHER, F BERGENFIELD, NEW JERSEY.

Application filed May 19,

Thisinvention is an electric switch and while adapted for general use isparticularly enable the circuit or circuits which it controls toproperly carry out its functions.

WVith these considerations in mind, the switch of the present inventionembodies mechanism electrically operable by a motor circuit, controllercircuit or by some other circuit associated with either of thesecircuits for the purpose of bringing normally spaced contacts of asignal resetting circuit into engagement and subsequently out ofengagement with respect to one another and for controlling the timefactor of such en gagement, so that while the contact may be said to bea momentary one, its duration is suclrthat the electrical adjuncts insaid resetting circuit will operate to carry out their functions duringthe actual period of on gagement between said contacts.

The present invention thus obviates certain difficulties in priorpractice arising from the operation of the resetting circuit.

through too short 'a period to effect resetting of thesignals andalsoarising fromthe energizing of the resetting circuit for a pe-v riodgreater in excess to that required for its functioning, the result ofthe latter course usually being'the burning out of magnets.

included in such circuit. 7

In my prior Patent'No. 1,333,240, issued March 9th,1920,I disclosedapump operated switch intended for the purpose of timing the periodofoperatio'n' of an electrical circuit,but in that instance the pump wasmechanically operated directly from some movable part of the elevatorinstallation, preferably the Practicehas proven that when used in thisconnection ,jit.is subjected to excessive'wearand moreover it was foundthat theLpump couldnotbe absolutely relied upon. V

.. derstood as illustrative, only, and not as dein theevent that the carwas run very slowly ELECTRIC SWITCH.

1923. Serial No. 639,999.

the action of the pump to control theswitch was too sluggish in itsoperation and there was no uniformity in the contact period. lVith thepresent invention, in contradistinctionpthe contact period will beuniform irrespective of the speed of the car and will be constant underall conditions.

A further feature of the present invention resides in the fact that theswitch of this invention may be regulated to give the-desired timeinterval oetween circuit closing andopening, thereby enabling perfectadjustment of the parts to the particular installation with which it isassociated.

lVhile the invention may partake of different practical forms,itconsists in one of its practical embodiments in-a solenoid coilincluded in a suitable circuit and with this 0011 isassociated a coreoperative within a cylinder coaxially of the coil of the solenoid.

The cylinder is adapted to contain fluid. The core normally gravitatesto the lower end of the cylinder and by such operation causes thefloatto be forced into the upper portion of the cylinder. However, when thesolenoid coil is energized, the core is drawn upwardly, creatingapartial vacuum beneath it which causes the fluid to pass by the coreinto the lower portion of the cylinderduring which operation themovement ofthe core is relatively sluggish depending upon the adjustmentoft-he parts. When the coil is deenergized the core again descends bygravity under the cushioning effect of the fluid which returnsto theupper part of the cylinder pastthe core.

By controlling the normal position of the core with reference to thecoil of the solenoid, the speed of operationot the core may be variedorregulated. The core is utilized to actuate a switch which is adaptedto be closed and subsequently opened by the movement of the core, sothat by regulating the speed-of movement of the core or its travel, theclosing and opening of the switch may be properlytimed.

5 Features of the invention, other than those specified, will beapparent from the hereinafter detailed description and claims, whenreadin conjunction with the accompanying drawings.

"lheacc mpanying drawings illustrate one practical embodiment oftheinvention, but the construction therein shown is to be unthe limits ofthe invention:

Figure 1 is an elevation of switch and operating mechanism embodying thepresent invention.

Figure 2 shows the construction of Figure 1 with the operating apparatusin central section; and,

Figure 3 is a section of a valve associated with the core and thissection is taken on the line 33 of Figure 2.

Referring to the drawings, 1 designates an elongated tube or cylinderclosed at its lower end as by a rubber plug 2 and guided for verticaladjustment in brackets 3 formed on a switch plate 4. The bracket 3 has adepending flange 5 which is tapped to receive two screws 6 which passthrough slots 7 in a supporting plate 8, the lower end of which is bentforwardly at right angles to the plate 8 and forms a foot adapted tosupport the lower end of the cylinder 1. The cylinder I may bevertically adjusted by loosening the screws 6 and sli ing the supportingplate 8 vertically and thereupon again tightening the screws 6 to lockit in position.

Encircling the cylinder 1 between the brackets 3 is a solenoid coil 9.In practice, this coil may be in the form of a winding, but for thepurpose of illustration I have shown two coils connected in series by awire 10. These two coils however function as ,a single coil. The coils 9are maintained in position by pressure screws 11 which are threadedthrough the upper bracket 3 and bear on the top of the coils to clampthem.

tightly against the lower bracket 3. The coils are thus mounted in fixedposition while the cylinder is longitudinally adjustable coaxially ofthe coils.

The core 12 of the solenoid is cylindrical and is loosely positionedwithin the cylinder 1 as shown best in Figure 2. With this top isassociated a disc valve or piston 13 adapted to fit the interior of thecylinder more tightly than the core 12. The stem 14 of the core extendsupwardly through a hole in the center of the valve 13, the hole 15 ofwhich valve is somewhat larger than the stem 14 as shown in Figure 3, soas to permit fluid to pass through the hole 15 and. around the stem 14.The bottom of the valve is shown as substantially flat but with radialchannels 16 through which fluid is adapted to circulate.

The solenoid is included within a suitable circuit 17. which whenenergized, energizes the coil and causes the core to be elevated. Thecylinder 1 contains a fluid which when the core is depressed isdisplaced by the core and forced into the upper part of the cylin-,

der. However, when the core is raised under the impulse of the coils, apartial vacuum is produced within the lower part of the cylinder andbelow the valve 13 and the core can only be elevated by the coil at aspeed substantially proportional to the rate at fect electric connectionwill result.

which the fluid can flow from above the valve past the valve and intothe lower portion of the cylinder. Thus the speed of the core in anupward direction under the impulse of the coils is controlled by thespeed with which fluid can pass by the valve and into the lower part ofthe cylinder. The speed of the core will therefore be held down so thatits movement will be relatively slow or at least much slower than wouldbe the case if it were not under the cushioning action of the partialvacuum created through this movement.

\Vhen the coil is deenergized, the weight of the core will cause it toreturn to the bottom of the cylinder and in so doing its weight will beimposed upon the fluid which will be forced upwardly past the valve toits initial position in the upper portion of the cylinder. The operationof the core in both directions will therefore be cushioned and itsmovement will be relatively sluggish.

The relatively slow movements of the core as described are utilized to ocrate one or more electric switches and while the switch constructionmay vary, I have shown the switch as consisting of a bell crank pivotedat its elbow on a bolt 18 passing through plate 4. One arm 19 of thebell crank is connected to the stem of the core 12 by means of a link20, while the other arm 21 of said bell crank constitutes a switch arm.The bell crank is insulated from the late 4, which, in practice, niay beof fibre a though it may be of metal with suitable insulating plates andbushings As the core is vertically reciprocatcd, it will, manifestly,oscillate the bell crank on its fulcrum 18 and in so doing will causethe arm 21. to be swung back and forth for the purpose of bringingcontacts associated therewith into and out of engagement with fixedcontacts carried by the plate 4. Any number of contacts may beassociated with the arm 21 andthey may be secured thereto in differentways. However, for the purpose of illustration, I will describe thestructure as shown in the drawln s.

n this showing, current is led through wire lead 22 to a metallic plate23 which is in electrical contact with the bolt 18 and in order toassure absolute electrical connection between the bolt and the bellcrank I may secure said bolt to the bell crank by a flexible lead 24, asshown in Figure 1, so that per- Current is therefore fed through thelead 22 to the bell crank which forms one terminal of the circuit.

25 designates a metallic plate to which is secured a wire lead 26 and tothis metallic plate is pivoteda contact 27, the right hand side of whichis exposed to contact with the lower end of the arm 21, while theopposite side of which has secured thereto an insulating strip 28. Aspringi29 normally maintains the contact 27 in upstanding position andin the path of a knob 30 formed at the lower end of the arm 21 ofthebell crank. With this construction, will beapparent that when thesolenoid is energized, the core will be elevated and will oscillate thebell crank in a clockwise direction as viewed in the drawings to bringthe knob 30 into engagement with the uninsulated part of the contact 27for the purpose of completing the circuit between the leads 22 and 26,The knob 30 will engage with' thecontact 27 while the latter is inupstanding position and as the bell crank is slowly tilted it will forcethe contact 27 from the dotted line position of Figure 2 into the fullline position of'this figure against the tension of the spring 29 andthis operation will continue until the contact 27 has been tilted farenough for the knob 30 to ride past the end of said contact whereuponthe spring 29 will immediately return the contact to upstandingposition, thus breaking thecircuit which was previously made. Thecircuit will remain open no matter how long the solenoid remainsenergized and when it is deenergized and the core proceeds to descend,the swinging of the arm 21 back into its normal position will cause theknob 30 to engage with the insulating strip 28 and rock the contact 27far enough to permit the knob to pass by this contact without howeverhaving completed this circuit during such return movement. It will thusappear that by regulating the speed with which the core is elevatedunder the impulse of the coils, the duration of contact between the knob30 and the contact 27 and the consequent duration of energizing of thecircuit of which the leads 22 and 26 form a part may be controlled. Thespeed with which the core will be elevated will depend upon theadjustment of the supporting plate 8 since the lower the core ispermitted to normally gravitate the slower will be its elevation notonly because it will have a longer distance to travel, but because itwill be further removed from the magnetic center of thecoils. I am thusable by regulating the position of the cylinder to regulate the intervalor duration of the energizing of the circuit 2226.

Additional switch mechanism may if desired be associated with the arm21, such for example as the arm 31, which is pivoted to the arm 21 at 32and is adapted to engage with the fixed contact 33 having an associatedlead 34. The arm 31 is shown as provided with an insulating strip 35which when the arm 21 is in normal position engages with the contact 33and breaks the circuit of which the lead 34 forms a part. However, whenthe arm 31 is oscillated by the core, the uninsulated part of the arm 31will make electrical connection with the contact 33 insulating strips 35may be so associated aS to either permit normalelectrical connection orelectrical connection only when the arm 21 is operated. I i i In theforegoing detailed description of the invention, I have referred to afluid as contained within the cylinder 1 and I wish this phraseology tobe construed broadly as meaning any fluid. This I may use either air,liquid or a gas, though inpractice I preferably use one of the lightoils such for example as kerosene, the evaporation of which is very slowand which liquid is sufficiently light and mobile, so as not to renderthe operation of the solenoid unduly sluggish. In practice, the cylinder1 may be of glass, butI preferably make it of brass or copper and insuch cases associate with the cylinder a sight tube or gauge glass 36which not only serves to show the height of the liquid, but also servesas a reservoir to compensate for slight evaporation.

It will be noted that in the foregoing detailed description of theinvention I have not attempted to state the particular circuits of whichthe loads 22, 26 and 34 form parts as this is really immaterial.However, these leads are usually parts of the resetting circuits of anelevator signalling system wherein it is desirable to obtain asubstantially momentary energization thereof, but one of sufficientduration to insure proper operation of the electrical instru mentsincluded in such circuits. I wish it understood however that I do notlimit the invention to the particular circuits shown or to theparticular arrangement of circuits or to the specific switchconstruction illus trated, as variations in this switch structure willreadily suggest themselves to those skilled in the art. I

The'coils of the solenoid may be introduced or associated with the motorcircuit, the controller circuit or with any other circuit, either inseries or multiple or, said coils may be included in independentcircuits adapted to be controlled by any movable part of the elevatorinstallation.

The invention is therefore to be understood as not limited to thespecific showing of the drawings but is to be understood as fullycommensurate with the appended claims.

Having thus fully described the invention,

what I claim as new and desire to secure by Letters Patent is: v

1. In an apparatus of the character described, the, combination with aswitch of an upstanding cylinder closed at its lower end and containinga liquid, a solenoid coil embracing a portion of the length of saidcylinder, a solenoid core within the cylinder and normally positioned inremoved relation to the magnetic center of the coil, valvular meansassociated with said core to permit liquid in the cylinder to by-passthecore during movement of the latter longitudinally of the cylinder tocushion the operations of the piston, and mechanical connections betweenthe core and the switch for securing these parts to one another.

2. In an apparatus of the character described, switch mechanismembodying-a pivoted lever, circuit closing means connected with the workarm of said lever, in combination with an upstanding cylinder closed atits lower end and containing a liquid, a solenoid coil embracing aportion of the length of said cylinder, a solenoid core within thecylinder and normally positioned in removed relation to the magneticcenter of the coil, valvular means associated with said core to permitliquid in the cylinder to bypass the core during movement of the latterlongitudinally of the cylinder to cushion the operations of the piston,and mechanical mam connections between the core and the power arm ofsaid lever for securing these parts together.

3. In an apparatus of the character described, switch mechanismembodying a pivoted lever, circuit closing means connected with the.work arm of said lever, in combination with an upstanding cylinderclosed at its lower 'end and containing a liquid, a solenoid coilembracing a portion of the length of said cylinder, a solenoid coreWithin the cylinder and normally positioned in removed relation to themagnetic center of the coil, valvular means associated with said core topermit liquid in the cylinder to bypass the core during movement of thelatter longitudinally of the cylinder to cushion the operations of thepiston, mechanical connections between the core and the power arm ofsaid lever for securing these parts together, and means for regulatingthe position of the cylinder with respect to the coil.

' I11 testimony whereof I have signed the foregoing specification.

. FRANZ A. BOEDTCHER.

